1. Field of the Invention
The present invention relates to a semiconductor device including silicide film and a method for manufacturing the same.
2. Description of the Related Art
A semiconductor device which has been progressed in miniaturization recently, for example, a MOS transistor employs salicide process for reducing parasitic resistance of the device. The salicide process is a process for forming the silicide films on source/drain regions and polysilicon gate electrode in self-align manner.
A nickel silicide film is know as one of the silicide film (“Silicide for 65 nm CMOS and beyond” written by Kittl, J. A.;Lauwers, A.;Charmirian, O.;Van Dal, M.;Akheyar, A.;Richard, O.;Lisoni, J. G.;De Potter, M.;Lindsay, R.;Maex, K. CMOS Front-End Materials and Process Technology. Symposium (Mater. Res. Soc. Symposium Proceedings Vol. 765) (USA) xi+308 P.P. 267-78). In the normal salicide process using the nickel silicide film, nickel monosilicide (NiSi) films are formed on the source/drain regions.
The NiSi films formed on the source/drain regions reduce contact resistance between the source/drain regions and source/drain electrode.
However, an interface between the source/drain regions and the NiSi films is not flat, so there is possibility that junction leakage current is not reduced by the NiSi films if the miniaturization further progresses (Lg<50 nm) hereafter.